Gardaí are investigating if a teenage girl was involved in the murder of Cameron Reilly, it has emerged.

The 18-year-old student was found strangled and beaten in a field in Dunleer, Co Louth, at the weekend.

His remains were found at 8.30am on Saturday, but gardaí believe he was murdered hours earlier.

A group of up to 20 male and female teenagers had been drinking and socialising in the area the day before his remains were found. It's believed that only a small number of people were present when the murder happened.

Detectives have identified a number of people - including teenagers known to Cameron - who were either involved or witnessed the murder. A female juvenile is also believed to have been present at the time.

A source last night told the Irish Independent: "The number of people present when Cameron was murdered is being whittled down, and a girl is believed to have been there."

Mourners gather at St Brigid’s Church in Dunleer for a vigil for Cameron Reilly, whose body was found at the weekend. Photo: Steve Humphreys

Gardaí believe that Cameron died as a result of manual strangulation in the early hours of Saturday. He also suffered injuries to his teeth and face, consistent with being assaulted.

Last night, gardaí were continuing to search for the victim's mobile phone - an Apple iPhone 8 with a green cover - which they believe will prove central to the investigation. "We would ask home and business owners in Dunleer to check their property, including wheelie bins and waste skips. We would also ask anyone offered a phone for sale as described to contact us," Inspector John O'Flaherty said.

CCTV footage from a local takeaway, not far from where his body was found, shows the last known movements of the young man.

Yesterday, youths could be seen escorting gardaí around the field where Cameron's body was found.

Friends of Cameron were still deeply upset yesterday.

"I used to be his best friend when we were in school," said one young woman. "He never once got himself into trouble and was as loyal as they come."

In a heartbreaking Facebook post over the weekend, Cameron's mother Tracy Glass said the family's hearts "are broken in a million pieces" and added: "My beautiful son love u to the moon and back."

Last night, hundreds turned out for a candlelit vigil in St Brigid's Church as the local community mourned.

Gardai gather amongst mourners at St. Brigid's Church in Dunleer for the Vigil for Cameron Reilly whose body was found at the weekend.
Photo: Steve Humphreys

Cameron had been studying hospitality at Dundalk Institute of Technology and a number of staff and students arrived to pay their respects. One of the young man's lecturers, Mairead McKenna, said "we're absolutely torn up" by his death.

Another lecturer, Michael McNamara, said many of the students met at the college yesterday. "I'm gutted, absolutely gutted, just wondering what kind of society we're living in now," he said.

Parish priest Fr Michael Murtagh said people in attendance wanted to show support to his family "and to take a stand for all that is decent and good in this world".

"We welcome Cameron's family and everybody who has joined us this evening.

"Our hearts and prayers are with you in a very particular and special way," he said.

Inside the church, a large wall had been created with pictures of Cameron and some of his many friends and best memories.